The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingTire and wheel system
Inspection
Inspect tire
Check the tires for wear and proper inflation
pressure.
Standard cold tire inflation pressure:
220 kpa (2.2 Kgf/cm2, 32 psi)
Using a dial indicator, check the runout of the tires.
Standard tire runout:
1.0 Mm (0.039 In.) Or less
Rotate tire
...
Disposal
Hint:
When scrapping a vehicle equipped with an srs or disposing
of the curtain shield airbag assembly, be sure to deploy the
airbag first in accordance with the procedure described
below. If any abnormality occurs with the airbag deployment,
contact the service dept. Of toyota motor sales,
u. ...
Short in front passenger side squib circuit
Description
The front passenger side squib circuit consists of the center airbag sensor
and the front passenger airbag.
The circuit instructs the srs to deploy when the deployment conditions are met.
These dtcs are recorded when a malfunction is detected in the front passenger
side sq ...